|Ordered:||15 September 1915|
|Builder:||AG Weser, Bremen|
|Laid down:||4 August 1916|
|Launched:||3 July 1917|
|Commissioned:||12 August 1917|
|Fate:||Depth-charged and sunk 25 April 1918. 41 dead, 1 survivor.|
|General characteristics |
|Class and type:||German Type U 57 submarine|
|Height:||8.25 m (27 ft 1 in)|
|Draught:||3.65 m (12 ft)|
|Propulsion:||2 shafts, 2 × 1.65 m (5 ft 5 in) propellers|
|Test depth:||50 m (164 ft 1 in)|
|Complement:||4 officers, 32 enlisted|
|Victories:||8 merchant ships sunk 10,795 GRT|
SM U-104[Note 1] was a German Type U 57 U-boat during the First World War. U-104 was built at AG Weser in Bremen, launched on 3 July 1917 and commissioned on 12 August 1917. She completed four patrols under Kptlt. Kurt Bernis and was responsible for the sinking of eight vessels of a total of 10,795 gross register tons (GRT). Among these was the American lightship LV 71, stationed at Diamond Shoals; the latter reported the submarine's presence in the area, at which point Bernis notified the lightship of his intentions and allowed her crew to depart before shelling the vessel and sinking her.
On 25 April 1918 the U-104 was engaged by USS Cushing in St. George's Channel and severely damaged. Later the same day HMS Jessamine came upon her and dropped further depth-charges, sinking her and leaving but a single survivor of her 42-member crew. The wreckage lies at position Coordinates: .
Summary of raiding history
|26 October 1917||Sapele||United Kingdom||4,366||Sunk|
|15 December 1917||Maidag||Norway||1,253||Sunk|
|21 December 1917||Spro||Norway||1,507||Sunk|
|25 December 1917||Ajax||Denmark||1,018||Sunk|
|2 March 1918||Kenmare||United Kingdom||1,330||Sunk|
|12 April 1918||Njaal||Russian Empire||578||Sunk|
|16 April 1918||Widwud||Russian Empire||299||Sunk|
|22 April 1918||Fern||United Kingdom||444||Sunk|
- "SM" stands for "Seiner Majestät" (English: His Majesty's) and combined with the U for Unterseeboot would be translated as His Majesty's Submarine.
- Tonnages are in gross register tons
- Gröner 1991, pp. 12-14.
- Helgason, Guðmundur. "WWI U-boat commanders: Kurt Bernis". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 26 January 2015.
- Helgason, Guðmundur. "WWI U-boats: U 104". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 25 January 2010.
- Helgason, Guðmundur. "Ships hit by U 104". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 26 January 2015.